Does not work with data binding

[slavasav]

Xml:
<io.techery.properratingbar.ProperRatingBar
android:id="@+id/rating"
style="@style/Rating"
app:prb_defaultRating="@{model.rating}"
android:layout_height="wrap_content"
android:layout_width="wrap_content" />
Error: Cannot find the setter for attribute 'app:prb_defaultRating' with parameter type java.lang.Integer on io.techery.properratingbar.ProperRatingBar.

This works:
<io.techery.properratingbar.ProperRatingBar
android:id="@+id/rating"
style="@style/Rating"
app:prb_defaultRating="2"
android:layout_height="wrap_content"
android:layout_width="wrap_content" />